Extraction And Separation Of Cordycepin And Adenosine From Cultured Cordyceps Militaris And Inhibitory Effect On Oxidative Stress In Kidneys Of Diabetic Mice

Diabetic nephropathy(DN) is the most frequent and serious complications of DM and becomes the main cause of deaths in DM. It is believed to be influenced by multiple determints with the high glucose level as the initiation factor.According to the literature reports, but,strong oxidative stress is observed in DM and plays an important role in occurance and development.Therefore, it would be of great significant to improve oxidative stress for treatment and prevention of DN.Cordyceps militaris, one of the most valued traditional Chinese medicines, also an important food and medicine resource,which contains cordycepin, adenosine,and polysaccharide, et al.Cordycepin and adenosine, both of the most important ingredient, has the activities of antioxidant, immunoregulation and anti-aging,et al. In this study, the extraction and purification of cordycepin and adenosine were used to investigate the protection effect in diabetes nephropathy mice which was induced by a single intraperitoneal injection of Stretozotocin.To obtained a simple, effective, energy-saving, environmentally friendly method for preparation of cordycepin and adenosine from cultured cordyceps militaris.And to investigate the cordycepin and adenosine effection on the oxidative stress of diabetic nephropathy mice.Firstly, response surface design was used to optimize the enzyme-assisted extraction (EAE) of cordycepin and adenosine from cultured Cordyceps militaris.Subsequently,the product of cordycepin and adenosine was coupled with macroporous resin column chromatography (MRCC). Six factors, solid-liquid ratio,extraction temperature,extraction time,optimal pH.enzyme addition and kinds of enzyme were studied.And the optimal purification conditions was obtained by static and dynamic adsorption and desorpotion test with four kinds of macroporous resins Finally. Fifty-six Kunming mice were randomly divided into seven groups as normal control group, diabetic control group, positive drug control group.low and high dosage group of extraction of cordycepin and adenosine, low and high dosage group of purification of cordycepin and adenosine.Except for normal control group, the rest were induced to be diabetes mellitus(DM) mice by injections of STZ. Every group were fed on corresponding diet by intragastric administration. After six weeks.the activities of antioxidant enzymes in renal cortex, including catalase.superoxide dismutase, glutathione peroxidase and malondialdehyde were measured in the cortex of kidney.The main results of research are as follows:(1) The optimal EAE conditions were obtained following:solid-liquid ratio of 1:24, extraction temperature of 42℃,extraction time of 150min,protease addition of 1.5% and optimal pH 7.0.Under the above conditions, the extraction yield of cordycepin and adenosine can reach 86.45% and 70.06%, respectively.(2) Cordycepin(32.5% purity) and adenosine (29.9% purity) were obtained following the conditions:50mL(1BV) of sample solution with pH 8.0,150mL(3BV) of 70% ethanol concentration with 3BV/h of fiow rate,and the purification process with an overall recovery rate of more than 90%.(3) The contents of T-SOD and CAT significantly increased, and the kidney index ,the contents of MDA and NO decreased,while diabetic mice treated with purification of cordycepin and adenosine high dosage. Cordycepin and adenosine high dosage can inhibit oxidative stress in kidney and improve renal function in diabetic mice.